I just picked up the e280R a couple of weeks ago. It syncs to JRiver well, just make sure you have it in "Plays for Sure" mode. I had it in Rhapsody mode at first and it took me a while to figure that out.
As for album art, my luck was not good. My files are mostly wma. I have the art embedded in the file and I also have the folder.jpg in each album folder. I could not consistently get album art to work on the player.
I am impressed with the battery life of the player and I like the file organization and the scroll wheel. The volume cranks up really loud if you need it, no wussy volume here. My complaints are two: (1) the scroll wheel light is blindingly bright, and (2) there is some processing background noise (beeps, hums, whirs, stuff like that). I usually notice this when I change a song or the next song begins. I dont have experience with Ipods, so I wonder if they do this as well....
When I bought the player I did not have the intention of using its Rhapsody features, but I decided to give the free three month trial a try....why not, right? So far, I am liking Rhapsody and could see myself getting hooked. I guess I will see in three months whether I like it enought to continue paying. In the meantime, the downside is that I haven't been using my beloved JRiver Media Center as much......